Carotid body

The carotid body (from the Latin glomus " ball " and Greek kara "head" ) is a small, nodule- shaped Paraganglion, in humans at about 3 mm in diameter, at the bifurcation of the left and right common carotid artery ( carotid artery ). It consists of so-called ensheathing cells and chief cells, and also blood vessels and afferent ( pulling towards the brain) nerve fibers. The cells function as main chemoreceptors, which measure the oxygen and carbon dioxide partial pressure and the pH of the blood. When the oxygen partial pressure increases, the carbon dioxide partial pressure and lower the pH value, then set the main cells release chemical messengers, of which the most important adenosine triphosphate ( ATP) is. ATP activates ionotropic receptors, namely P2X receptors to the afferent nerve fibers, and the ramus of the glossopharyngeal nerve sinus carotici the information on the circulatory and respiratory center in the medulla oblongata is headed. Respiratory rate and depth are increased reflex.

Glomera with a similar function is also available in the wall of the aorta, namely the glomera aortica, and at other locations in the body.

The function as a chemoreceptor organ was discovered in 1930 by Jean -François Heymans and his son Corneille Heymans. The son received in 1938 "for his discovery of the role of the sine and Aortenmechanismus in respiratory regulation," the Nobel Prize for Physiology or Medicine.

In case of prolonged lack of oxygen, such as emphysema, the increased carotid glomus. Occasionally, tumors ( paragangliomas ).